Two-stage form-securing system

ABSTRACT

A SYSTEM FOR SECURING FORMS PREPARATORY TO POURING CONCRETE, IN WHICH THE FORM STRUCTURE IS HELD IN PLACE BY FORCES TRANSFERRED THROUGH AN INNER BOLT SECTION ENGAGING AN EMBEDDED ANCHOR, AN OUTER BOLT SECTION VERTICALLY ENGAGEABLE WITH THE INNER BOLT SECTION, A CAM MOUNTED ON THE OUTER BOLT SECTION, A BRACKET SUPPORTING THE CAM AND MOVABLY MOUNTED ON THE FORM, PREFERABLY A SECONDARY INTERLOCK BETWEEN THE OUTER BOLT SECTION AND THE BRACKET, AND AN ADJUSTING DEVICE FOR APPLYING FORCES BETWEEN THE FORM AND THE BRACKET AT LARGE MECHANICAL ADVANTAGE TO GENERATE STRESS IN THE BOLT SECTION AND HOLD THE FORM FIRMLY AGAINST THE FACE OF THE SET CONCRETE OF THE PREVIOUS POUR.

United States Patent 0 m9 H 9 W4 2 2 mum a a mmmmm i ii WHCWW 0234966666 99999 11111 29 ll I 9 786 84386 7 ,33 20 04 66766 J 23333 h c m mD. a R m r G s m mS mm a w 9 .n l 8 w 9 6% v. MMH. C347M r 0 m 8 n ym vp .m AF .1 ll. 2 2 7 22 l [l Primary Examiner-Charles W. LanhamAssistant Examiner-Ben D. Tobor Attorney-Glenn B. Morse Patented June28,1971 [54] TWO-STAGE FORM-SECURING SYSTEM 14 Claims, 27 Drawing Figs.

ABSTRACT: A system for securing forms preparatory to pouring concrete,in which the form structure is held in place by forces transferredthrough an inner bolt section engaging an embedded anchor, an outer boltsection vertically engageable with the inner bolt section, a cam mountedon the outer bolt section, a bracket supporting the cam and movablymounted on the form, preferably a secondary interlock between the outerbolt section and the bracket, and an adjusting device for applyingforces between the form and the bracket at large mechanical advantage togenerate stress in the bolt section and hold the form firmly against theface of the set concrete of the previous pour.

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m m 9 I488 N n n 999 m n N "H" .L In 302 C am 1 s M mun U IF 054 .l l]l. WEB 2 l0 6 U r 15 U 22 PATENTED JUN28 197i SHEET 1 OF 5 INVENTOR.Chester I. Williams ATTORNEY PATENTEU M28197;

SHEET 2 [IF INVENTOR. Chester l. Williams Q;m L

PATENTEUJUNZBIQY: 8,588,028

Fig. 26

INVENTOR, Chester I. Williams TWO-STAGE FORM-SECURING SYSTEM SUMMARY OFTHE INVENTION The construction of dams with concrete is a step-by-stepprocedure in which successive layers are poured with just enoughintervening time to permit each pour to set. The vertical (or inclined)face of the dam is established by forms confining the poured concrete,and these forms are held against the face of the dam by anchor devicesembedded in each pour as it is deposited. The accurate maintenance ofthe face of the dam as a continuous surface is dependent upon thealignment of the forms for each pour, and this phase of the work hasnecessarily been time consuming. The form sections are usually liftedand placed by a crane, and are then secured by special bolts engagingthe anchor devices. Lateral and vertical placement for engagement of thebolts has always been a problem, as well as the tightening of the boltswith enough prestress to withstand the tremendous pressure of concretepoured to a depth of to feet.

The present invention provides a new system for securing the formsections, which simplifies both the placement of the forms and also thestressing of the bolts. The bolt assembly that transfers forces from theembedded anchor to the form structure includes an inner section thatacts as a locating projection extending from the face of the concrete,and on which the form can be vertically and horizontally located by abearing component on the form structure. The placement of the form alsohas the effect of coupling the inner bolt section to an outer boltsection mounted on the form. This outer bolt section in ludes apreliminary clamping device that can be pulled down quickly and easilywith enough force to hold the form in place. The initial securing isfollowed by an adjustment of a bracket that supports the bolt on theform, and the effect of this adjustment is to apply the necessaryprestress to the bolt with much less effort than that involved in theconventional procedure (in which a nut is tightened directly on the boltagainst the form). Provision is made for uncoupling the bolt sections sothat the form can be backed off from the face of the concrete after thepour has set. This movement is necessary in order to clear the form fromthe newly placed anchor devices and inner bolt sections held in positionby the upper part of the form for embedment in the pour as it is cast.

DETAILED DESCRIPTION The several features of the invention will beanalyzed in detail through a discussion of the particular embodimentsillustrated in the accompanying drawings. In the drawings:

FIG. 1 is a sectional elevation of the portion of the form structuresurrounding the tie system, and shown in a position corresponding to thebeginning placement of the form by a crane.

FIG. 2 is a section of the structure shown in FIG. 1, with the initialplacement and securing completed.

FIG. 3 shows the position of the form structure and tie system as theform is backed off from the new pour after it has set.

FIG. 4 shows the position of the form following that of FIG. 3, in whichthe form is being pulled away from the new pour of concrete, at asomewhat inclined position.

FIG. 5 is a perspective view of the inner bolt section.

FIG. 6 is a view of the coupling structure associated with the outerbolt section.

FIG. 7 is a perspective view of the coupling shown in FIG. 6, from theopposite side.

FIG. 8 is a perspective view of the bracket mounted on the formstructure for supporting the outer bolt section.

FIG. 9 is a perspective view of the bracket shown in FIG. 8, from theopposite side.

FIG. 10 is a view of the rod portion of the outer bolt section.

FIG. 11 is an enlarged view of the rod section shown in FIG. It), with aportion of the length broken away to permit the use of a larger scalefor illustrating the configuration.

FIG. 12 is an elevation on a plane taken perpendicular to the elevationshown in FIG. llll. FIGS. l1 and 12 may be'considered as side and bottomviews, with regard to the projection relationship.

FIGS. 13 through 19 are sections on the corresponding planes 13 through19 of FIG. 12.

FIG. 20 is a front view of the cam an handle on the outer bolt section,showing its relationship with the bolt-supporting bracket.

FIG. 21 is a perspective view showing the cam. the outer bolt section,and its engagement with the supporting bracket.

FIG. 22 is a perspective view of a locating collar associated with atubular receptacle mounted at the upper part of the form for positioningan inner bolt section (together with an anchor device associated withit) at the upper portion of the form.

FIG. 23 shows the assembled relationship of the tubular receptacle andthe inner bolt section.

FIG. 24 shows an adjusting shim for altering the vertical relationshipbetween the form structure and the supporting bolts.

FIG. 25 is a perspective view of the positioning plate on the formstructure for engagement with the projecting portion of the inner boltsection for lateral and vertical positioning of the form.

FIG. 26 is a sectional elevation of the portion of the form on which thelocating plate is mounted.

FIG. 27 is a top view showing the assembled relationship of the tiesystem in the position in which the form is fully secured preparatory tothe casting of the next pour.

The form structure generally indicated at 30 includes a panel 31stiffened by a group of horizontal and vertically spaced beams 32.Forces from these beams are received by the pairs of so-called walers 33and 34 (refer to FIG. 27). These pairs of vertical beams beingpreferably channel-shaped in configuration, and separated by standardspacing. The distance from one pair to the next will commonly be on theorder of 4 to 8 feet. The illustrated form structure is of steel, whichis the usual type with which the present invention would be associated.The space between the vertical walers 33 and 34 is traversed by tiesystems of the type shown in FIG. 27,

these being vertically spaced by an amount related to the height of'theforms being used.

It is common practice to incorporate in the form structure some form oflocating receptacle for positioning an anchor to be embedded in thenewly cast pour so that it is available after the pour has set to tiethe form for the next succeeding pour. The developing face 35 of the damis established by the form structure, and the previous pour 36 containsan anchor device 37 embedded in it through proper placement by an innerbolt section 38 carried by the tubular receptacle assembly 39 shown inFIG. 23. After the pour 36 has set to the necessary strength, the innerbolt section 38 becomes available as a locating projection forpositioning the form structure 30 preparatory to making the new pour 40.The tie system 41 (referring to FIG. 27) is responsible for producingthe forces necessary to hold the form structure 33 in place against theterrific liquid pressure generated by the presence of the newly castconcrete forming the pour 40.

The embedded anchors 37 are essentially lengths of crimped steel rodheavily cold worked so that the yield point of the material is fairlyclose to the ultimate strength. This type of material is necessary, asany yielding of the anchor will result in displacement of the form, andthe strength of the anchor beyond that point is useless. The bestretention of the anchor in comparatively green concrete is obtainedthrough the use of the configuration described and claimed in my U.S.Pat. No. 3,160,988. The ability to sustain the necessary force in greenconcrete shortens the necessary intervening time between pours, andpermits the most effective use of the efficiency provided by theclamping system of this invention. The outer ends of the anchors 37 arethreaded for engagement with the internal threading at 42a on theconical inner end 42 of the inner bolt section 38. This threadedengagement is standard, and does not itself form a part of thisinvention.

Since the major portions of the form structure are relatively standard,it is desirable to provide the components of the present invention asattachments that can be applied to these otherwise standard structures.The panels 31 of the form are modified to the extent of providing holescapable of receiving the outside diameter of the tubular members 43, andthese members have flange plates 44 welded as shown at 45 to theperiphery at a point set back from the inner end an amount equal to thethickness of the plates 31, so that the inner extremity of the tubes 43is flush with the inside surface of the plates 31. The inner boltsections 38 are provided with an annular flange 46 that fully occupiesthe inside diameter of the receptacle 39, with the inner face of theflanges 46 also being flush, or coplanar, with the inside of the panel31. The flanges 46 have the primary function of excluding concrete fromthe interior of the receptacles 39 around the sections 47 of reduceddiameter that extend between the flanges 46 and the heads 48. It ispreferably that these heads be tapered outwardly to reduced diameter, asshown in FIG. 23, to accommodate a tilting of the form with respect tothe inner bolt sections as the form is removed from the set concrete.This same tilting action is further facilitated by providing moreclearance between the outside diameter of the head 48 and the inside ofthe receptacle 39 than is present between the inside of the receptacleand the flange 46. With this arrangement, the flange 46 serves thefunction of locating the bolt sections 38 with respect to the form, andprovides some increase in freedom to disengage the form from the head48. The axial placement of the bolt sections 38 with respect to the formis obtained through the use of a cross pin 49 which traverses suitablealigned holes in the tubular receptacle member 43 and the cross hole 50in the bolt section 38. When not in use, the pin 49 remains secured withrespect to the form by the presence of the chain 51 secured to thereceptacle 39 at the juncture of the flange plate 44 with the tubularmember 43. This connection is preferably made simply by welding one ofthe links in place.

When the form 30 is initially swung into place by a crane, it ismaneuvered so that ti approaches the position shown in FIG. 1. Thelocating plate 52 (shown in FIG. 25') is angular in configuration havingthe mounting flange 53 secured to the underside of the form structure bybolts 54 traversing the beam 32 of the form, and engaging the nuts 55welded to the underside of the flange 53. The center of the flange 53serves as an abutment receiving the end of the adjusting bolt 56 whichengages a nut similar to the nut 55, but which is welded to the upperface 57 of the beam 32, the beam being provided with a hole oppositethis welded nut to permit passage of the adjusting bolt 56. The bolts 54may be loosened to permit some degree of vertical displacement of theplate 52 with respect to the beam 32, and the bolt 56 may be adjusteddownwardly so that the weight of the form is transferred through thebolt to the flange 53. The bolts 54 may then be tightened selectively,if desired, to generate some degree of lateral adjustment of the form,using the bottom extremity of the bolt 56 as a fulcrum. The portion ofreduced diameter 47 of the inner bolt sections is received within theV-shaped lower edge 58 of the plate 52, and the final position of theform is such that the weight of the form is carried on the portion 47 ofthe inner bolt section, which rests against the central portion 59 ofthe lower edge of the plate. In this relationship, it will be obviousthat any angular adjustment of the plate by relative tightening of thebolts 54, with the adjusting bolt 56 acting as a fulcrum, will produce aslight lateral displacement of the form with respect to the supportinginner bolt sections 38. Lateral adjustability can also be provided by adegree of clearance in the unthreaded holes traversed by the bolts 54.It is inevitable that some accumulations of tolerance occur during theconstruction of the form and their successive placement on thesucceeding pours of concrete, and the adjustments provided here are usedto compensate for accumulating misalignment. When once the forms seen tobe properly aligned with respect to each other, it is normallypreferably to incorporate the shim plates 60 shown in FIG. 24 to fix therelative position of the locating plates 52 with respect to the formstructure. These shim plates are provided with cutout portions at 61-63for receiving the bolts 54 and 56.

When the form is initially lowered in position as shown in FIG. 1, thisaction not only serves to place the form vertically and laterally aspreviously described, but also engages the coupling portion 64 of theouter bolt section 41 with the inner bolt section 38. A simple form ofthis coupling is illustrated in FIGS. 6 and 7, and includes a pair ofside bars 65 and 66 welded to the opposite faces of a heavy nut 67. Atthe inner end of the bars 65 and 66, a yoke piece 68 is securely welded,with this piece having a normally downwardly open opening capable ofreceiving the portion 47 of reduced diameter of the inner bolt sections.The function of the yoke 68 is to slip behind the head 48, and therebypermit transfer of forces from the imbeded anchors 37, through the innerand outer bolt sections, to the form structure. A bar 70 is welded inplace so that it spans across between the bars 65 and 66 to strengthenthe coupling in the area adjacent the yoke 68.

The inner extremity of the rod 71 of the outer bolt section is threadedat 710 for engaging the nut 67 of the coupling 64. The outer extremityof this rod traverses the space between the plates 73 and 74 of thebracket 75 shown in FIGS. 8 and 9. These outer plates are welded to theopposite side plates 76 and 77, the inner edges of which are bridged onone side by the threaded member 78, and on the other side by theabutment piece 79. The attachment of the bracket 75 to the formstructure 30 is best shown in FIG. 27, and this attachment cen tersprimarily in the bolt 80. The side plates 76 and 77 are timed off asshown at 81 and 82 to provide fulcrum edges at 83 and 84 near a verticalplane containing the axis of the bolt 80, so that the bracket 75 iscapable of rocking a slight amount about this point. A limited freedomof movement for this rocking motion is provided by the spring washer 85interposed between the head of the bolt 80 and the bracket 75 so thatsome looseness is present. The purpose of the abutment piece 79 appearsmost clearly in FIG. 27, and it prevent s rotation of the bracket 75with respect to the form so that the bracket remains in a cantileverposition extending generally horizontally.

The outer extremity of the rod 41 has a diametral hole 86 receiving thecam pin 87. The opposite cam plates 88 and 89 are welded to the oppositesides of an actuating handle 90, which is of approximately the samediameter as the transverse dimension across the flats 91 and 92 at theend of the rod 41. The cams 8% and 89 are eccentrically mounted on thepin 87, and actuation of the handle will therefore vary the axialposition of the outer bolt section 41 with respect to the frame 30, withthe uncammed" position shown in FIG. 1, and the cammed position shown inFIG. 2. When in the fully cammed" position, it becomes possible toinsert the cross pin 93 through the aligned holes 94 and 95 of thebracket 75, and through the hole 96 in the rod 41. This cross pin willhave the effect of transferring the forces from the rod 41 to thebracket 75, and thus relieve the cams 88 and 39 after they haveperformed their function of positioning the form structure. It isdesirable that this direct transfer of force be made through the crosspin 93, as the intensity of these forces is tremendous. The manualactuation of the handle 90 has the effect of pulling the form down intoposition as shown in FIG. 2, but does not provide enough loading toeffectively prestress the tie system. This latter function is providedby the bolts 97 which bear against the flange 98 of the form structure,and are in threaded engagement with the members 78 best shown in FIG. 9.Tightening of the bolts 97 will cause the bracket 75 to rock about thefulcrum 83 and 84, and generate a stress in the rod M approximatelyequal to twice the force applied by the bolt 97. This feature ofmechanical advantage makes it possible to tighten the bolts 97 with farless effort than is otherwise the case. A direct tightening of thesecuring nut on a conventional form-securing bolt requires such a highdegree of torque, and the use of such a large torque wrench, as toproduce a considerable problem for the workmen. .By cutting this forcein half, and possibly by using a thread system on the bolt 97 of lesspitch than would normally be necessary on a direct bolting arrangement,a much smaller torque wrench can be used.

The spacing between the plate 73 and 74 is such that the bolt rod 71 canbe rotated to all angular positions about its axis only when theportions of reduced diameter 99, 100, or 101 are present in the spacedirectly between the plates 73 and 74. The rod 71 may move axiallybetween the portions 100 and 101 only when the axis of the pin 87 ishorizontal, and between the portions 99 and 100 only when the pin axisis vertical. When the handle 90 is swung downward or upward, as shown inFIGS. 1 and 2, the axial position of the pin 87 is horizontal. Theplacement of the portion 101 between the plates 73 and 74 corresponds tothe uncammed position of the outer bolt section. ln the cammed position,the portion 100 is between the plates 73 and 74. The length of theseportions is such as to provide an approximate axial positioning of theouter bolt section for the various stages of installing and removing theform. When the form is initially placed, it is desirable that the outerrod assembly be extended inwardly so that the yoke 68 can easily engagebehind the head 48 of the inner bolt section. The locking of this axialposition by rotating the handle 90 out of a vertical plane preventsaccidental jostling from displacing the outer bolt sections during thelocation ofthe form.

The manner of engagement of the bolt with the bracket obviously permitsa considerable amount of articulation of the axis of the bolt withrespect to the form, and the extended position of the handle (parallelto the axis of the rod 71) shown in H0. 3 will permit the handle to bepressed downwardly while the pin 87 is vertical and rock the outer boltsection up into the dotted-line position shown in FIG. 3 so that is canbe retracted in the direction of the arrow to a point where it will notreengage with the head 48. This position makes it possible to remove theform with a minimum amount of interference form the coupling 64. Theretracted position corresponds to a placement of the portion 99 ofreduced diameter between the plates 73 and 74, which is maintained byrotating the flats 104 and 105 out of alignment by manipulating thehandle 90 so that the axis of the pin 87 is off vertical. With thisfreedom of articulation of the outer bolt section, it is necessary toprovide some form of support on the form structure so that the outerbolt-section bolt remains generally horizontal during the placement ofthe form. The support bar 106 extends between the waler beams 33 and 34to perform this function, and it will be noted that downward movement ofthe form may easily result in the accidental jostling of the couplingmember prior to arriving at a position of alignment. This movement iseasily accommodated without putting any unnecessary stresses on the tieassembly. The angular position of the rod 71 about its axis willnaturally either be determined by the effect of gravity urging thehandle 90 to the downward position shown in FIG. 2, or by the cam plate89 resting against the jack bolt 97, with the handle 90 extendinglaterally. This intermediate position can be utilized to maintain thebolt in the fully retracted position, such that the portion 99 ofreduced diameter is embraced between the plates 73 and 74. With thehandle rotated counterclockwise from the position shown in P10. 1, theangular position about the axis can be maintained by the tendency forthe handle to rest between the beams 33 and 34, and thus preserve thefully projected position of the bolt assembly to assist in the couplingof the inner and outer sections.

The particular embodiments of the present invention which have beenillustrated and discussed herein are for illustrative purposes only andare not to be considered as a limitation upon the scope of the appendedclaims. In these claims, it is may intent to claim the entire inventiondisclosed herein, except as I am limited by the prior art.

lclaim:

1. A system for securing a form for confining poured concrete, the formhaving a concrete-retaining panel and beam means disposed to transferstress from said panel to securing bolt means engaging an embeddedanchor, wherein the improvement comprises:

a bracket mounted on certain of said beam means, said bracket having anopening:

an outer bolt section received in said opening, said outer bolt sectionbeing movable axially with respect to said bracket and having couplingmeans of the inner extremity of said outer bolt section;

pulldown means having portions thereof disposed to bear on said bracketand said outer bolt section, and operative to axially position saidouter bolt section with respect thereto;

means for adjusting under stress the position of said bracket withrespect to said fonn in the direction perpendicular to said panel toprestress said system; and

an inner bolt section normally projecting from the face of the concreteestablished by said panel, and engageable to one end with said anchor,and at the other end with coupling means.

2. A system as defined in claim 1, wherein said form additionallyincludes a locating member vertically engageable with said inner boltsection, and having a lower edge converging upwardly for laterallypositioning said form means by engagement with said inner bolt section.

3. A system as defined in claim 2, wherein said form is supportedvertically on said edge.

4. A system as defined in claim 3, wherein said locating.

member is adjustable vertically with respect to said form.

5. A system as defined in claim 1, wherein said coupling means and innerbolt section are provided with interrelated configuration whereby saidcoupling means is vertically engageable and disengageable from saidinner bolt section.

6. A system as defined in claim 5, wherein said outer bolt section ismounted on said form with a freedom of movement whereby said outer boltsection it tiltable in a vertical plane with respect to said form.

7. A system ad defined in claim 1, wherein said bracket has one sidesecured to said form with limited freedom to rotate about a fulcrum, andsaid bracket has adjustable jack means at the opposite side thereof, anddisposed to bear on said form.

8. A system as defined in claim 7, additionally including auxiliarysecuring means interengaging said outer bolt section and said bracket.

9. A system as defined in claim 1, wherein said pulldown means includesa cam mounted on said outer bolt section for rotation on a transverseaxis, and engageable with said bracket, said cam having actuating handlemeans.

10. A system as defined in claim 9, wherein said outer bolt section ismounted on said form for rotation about the axis of said outer boltsection in said bracket, and said coupling and inner bolt section haveinterengageable configurations whereby said coupling is rotatable onsaid inner bolt section.

1 1. A system as defined in claim 10, wherein said outer bolt sectiontraverses an opening in a member fixed with respect to said bracket,said opening and outer bolt section having interrelated configurationwhereby said outer bolt section is axially movable with respect to saidbracket only in selected angular positions about the axis of said bolt.

12. A system as defined in claim 1, wherein said form additionally has atubular receptacle defining an opening in said panel, and disposed toreceive an inner bolt section in position for embedment, said inner boltsection having a head and a portion of reduced diameter adjacent saidhead, said inner bolt section also having a flange disposed to occupythe said panel opening, said receptacle also having disengageable meanssecuring said inner bolt section with respect thereto.

13. A system as defined in claim 12, wherein said inner bolt section hasthe head thereof tapering outwardly to reduced diameter, and said headhas greater clearance within said receptacle than has said flange.

d in olaim 22, wherein said portion of mam with said reduced diameterfor laterally positioning said ds substantially from said flange toform, said plate being set outward from the plane of the inside .s-Qidform additionally includes a loca'tface of said fonn panel an amount atleast equal to the oz'dly fol engagethickness of said flange.

